ASHRAE-90.1-2022- - Page 044

Extracted Content

5. BUILDING ENVELOPE

5.1 General

5.1.1 Scope. Section 5 specifies requirements for the building envelope .

5.1.2 New Buildings. Building envelope components installed in new buildings shall comply with the requirements of Section 5.2. 2nd choice: prescriptive or trade-off w/ required for all paths.

5.1.3 Additions to Existing Buildings. Building envelope components installed in additions shall comply with the requirements of Section 5.2.

5.1.4 Alterations to Building Envelopes. Alterations to the building envelope shall comply with the requirements of Section 5.2 for insulation, air leakage, and fenestration applicable to those specific portions of the building that are being altered.

Exceptions to 5.1.4: The following alterations need not comply with these requirements, provided such

alterations will not increase the energy use of the building :

1. Installation of storm windows or glazing panels over existing glazing, provided the storm window or glazing panel contains a low-emissivity coating. However, a low-emissivity coating is not required where the existing glazing already has a low-emissivity coating. Installation is permitted to be either on the inside or outside of the existing glazing.
2. Replacement of glazing in existing sash and frame, provided the U-factor and SHGC will be equal to or lower than before the glass replacement.
3. Alterations to roof, wall, or floor cavities that are insulated to full depth with insulation having a minimum nominal value of R-3.0/in.
4. Alterations to walls and floors, where the existing structure is without framing cavities and no new framing cavities are created.

element requirements for roofs in Tables 5.5-0 through 5.5-8 and Section 5.5.3.1.4. 8. Replacement of existing doors that separate a conditioned space from the exterior shall not require the installation of a vestibule or revolving door, provided that an existing vestibule that separates a conditioned space from the exterior shall not be removed.

42 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)